Catapult Construction

[PAR_WIG1350]

Trebuchets ARE catapults. The difference is trebuchets are gravity powered catapults rather than torsion catapults. Also, despite the bend in the arm, the second picture appears to be a trebuchet, or a hybrid catapult.
You will probably get more out of surgical tubing then rope. Using both might be even better. also, not to discourage you, but bowling balls can break if dropped/bounced. It happened once on Mythbusters.

[DonRotolo]

Originally Posted by Ultramadscienti

actually I should run a script to see how would be the most efficient way to curse it.

That would be cool. Post the results here.

Originally Posted by PAR_WIG1350

despite the bend in the arm, the second picture appears to be a trebuchet

Yeah, maybe, but I picked that image because of the bend in the arm, nothing more.

Catapults are a class of things to fling things. Trebuchets are in the Catapult class. Do not fling cats, please (even though they make a wicked cool "pult" sound when they hit)

No animals were harmed in the making of this post.